Wheat is one of the main food allergens. It is among widely used cereals and there is an extensive cross-reaction between cereals. The aim of this study is to evaluate the extent to which cereals cross-react and to find the best substitute for wheat. Eighteen patients with definite diagnosis of type I hypersensitivity reactions to wheat enrolled in this study. Measurement of serum-specific IgE and skin prick test (SPT) for cereals flour (wheat, barley, oat, rye, rice and corn) and wheat bran was carried out. Also, open food challenge tests with available and conventional cereals in Iranian food culture (wheat, corn, rice and barley) were carried out. The SPTs were positive in 44.4% of patients for barley, 94.5% for wheat and 44-77% for other cereals. Positive serum-specific IgE was remarkable for wheat and barley and there was correlation between wheat and barley-specific IgE concentrations (r = 0.773 and p < 0.01). Corn serum-specific IgE was measured in 10 patients, which were positive in six of them. Of the patients, 55.5% had positive barley challenge tests, but all corn and rice challenge tests were negative. The best substitutes for wheat in wheat allergic patients are rice and corn. Regarding the correlation of wheat and barley serum-specific IgEs, there might be a high antigenic cross-reaction, therefore barley is not a good substitute for wheat and consuming barley needs a careful challenge test. Considering concordance of positive SPT to wheat flour and wheat bran, avoiding both of them is necessary in patients with wheat allergy.
Copyright 2005 Blackwell Munksgaard